Brake adjuster



July 4, 1950 l-l. E. BARrscH 2,513,275

BRAKE ADJUSTER -Filed Aug. 30, 1946 3 Sheets-Sheet 1 v 2 la.;y

"Flu JUN? 4 W5 H. E. BARTscH KUHN BRAKE ADJUSTER Filed Aug. 50, 1946 3Sheets-Sheet 2 Patented July 4, 1,950l

uNiTe-o i s TAT; s

"TENT OFF] C E Vlana-int ADJUSTER Delaware Application Augustl), 1946,Serial No. 694,047

(Cl. 18S-496) Z-Claims. 1 l.

My invention relates to adjustmentdevices for taking up the slack in thefoundation brake .gear of Arailway cars, and more particularly relatesto a rotary slackadjuster adapted to he mounted under a car to take upexcess slack in .the brake gear.

In a brake adjuster of the present general type a flexible means, in theform of 4a chain, is con necte'd .at one end to the floating lever ofthe foundation brake gear, and Vis connected at its other end to asheave to be taken up by the sheave whenever it is desirable to adjustthe piston travel. Means is provided to actuate the sheave in adirection to take up the chain, along with releasable means to prevent,or at least to limit, reverse rotation of the sheave.

An important object or my invention is to mini- 7 mize the possibilityof failure on the 'part of the pivotmeans or shaftlthat rotatablysupports the slack 'adjusting sheave.` This is accomplished largely bydevising a mechanism in which the pivot means or shaft for the sheaveserves solely as a `fulcrum lmeans inthe transmission lof forces. In'other words, it is contemplated 1in the present invention that forcesboth for rotating the sheave and for resisting rotation rof the sheavewill be applied to the sheave itself `directly and not through the pivotmeans or shaft on which the sheave is mounted. Such an arrangement is incontrast to the usual combination inwhich`1the force for rotating thesheave in artakeup direction and] or the force for resisting rotation inthe opposit'e'zlirection involve the placingof the sheave shaft undertorque stress. There is much less likelihood of such a pivot means orshaft failing with serious results if it isrequired Ito serve solely asa simpjle fulcrum means and is never placedunder appreciable torque.

A further purpose of my invention is to provide such a slack adjustingmechanism of relatively light .aggregate weight. A specific object inthis regard fis kto provide such a .mechanism in whichthe weight ofparts may be greatly reduced in the light of current practice withoutany `.risk whatsoever that failure `of the -lightened parts willjeopardize Vthe Vfunctioning :of the brake mechanism. With :referencetto lightness of iweight this object is attained by incorporatingreduction gearing in the Vslack .adjusting mechanism wherebythemechanism may be actuated for slack takeup froma remote pointwitharelatively light 1 actuating force. Thus the slack adjusting mechanismproper may be placed near .the center sill of a-railway car and operatedremotely from tile side of v'the car by means of a Vrelativelylightweight shaft suitably adapted for manual rota-` tion. As for theavoidance of risk in the use ofsuch .a 'light-weight shaft, by employingratchetv Ameans directly cooperative ywith the sheave to prevent reverselrotation thereof I avoid involving the light actuating shaft in the`application of brake-applying forces so that failure of the relativelylight shaft cannot aiect `brake operation.

Other yobjects of lthe invention include Ithe following: to provide aslack adjuster that may` either besold `.asA a unit for installation onvexisting cars or may be incorporated Ain the construction of new cars;to provide a slack adjusting mechanism including a chain-winding rsheavein which the vforcesfor rotating the sheave 'in one direction, and foropposing rotation inthe other direction, are applied directly to thesheave `itself at a relatively great radial distance from the sheaveaxis; and to provide such a slack `adjuster in which the yprincipalworking parts are arranged compactly in a housing adapted for mountingon or near the center sill of a railway car.

. Other objects and advantages of my invention will be apparent from thefollowing descriptiorr taken with the accompanying drawings. l

In the drawings, which are to be regarded as illustrative only:

Fig. 1 is Aa semi-diagrammatic view showing an application of the slackadjuster to the foundationzbrake .gear of `a standard freight car;

Fig. 2 isan end elevation'of the slack adjusting mechanism as viewedfrom the side of the car;

Fig. 3 is .a transverse section on a slightly elnlarged scale, taken as`indicated by the line 3-3 of Fig. "l, the view showing the slackladjuster. housing 1with parts broken away;

Fig. 4is a similar view from the opposite side of the housing, with.parts of the housing broken away;

Rig. '.5 is a perspective View, on `an enlarged scale, of a pawlemployed in the mechanism;

Fig.l 6 `is ga section lone. greatly venlarged scale, taken as indicatedby the line 6--5 of Fig. `3 and I p cylinder lever or floating lever I8,tie rod 20, toprods 2|, live truck levers 22, intermediate rods 23, anddead truck levers 24.

In the particular embodiment of the invention chosen for thisdisclosure, adjustment of the foundation brake gear is accomplished byshifting the fulcrum 25 of the floating lever I8, but it will beunderstood that such adjustment may also be accomplished in other ways,for example, by y shifting the fulcrums 26 of the dead truck levers 24.

The major parts of the brake adjusting mechanism are enclosed in asuitable support or housing, generally designated 21, mounted on the carat a substantial distance inward from the side of the car and relativelynear the center sill II. This housing 21 is preferably made in twosections 28 and 29, which are united by suitable bolt means 30 extendingthrough ears 3l. The housing may be mounted on the car in any suitablemanner. In the construction shown in the drawings the housing section 28is formed with wings 32, reinforced by webs 33, the wings beingapertured at 35 to receive rivets. The housing is shown riveted to apair of brackets 36, which brackets are in turn mounted on the web ofthe center sill I I by means of rivets 31.

Inside the housing 21 a pivotal mounting means, in the form of a stubshaft 40, is seated at its opposite ends in sockets 4I and 42 formed inthe housing sections 28 and 23, respectively. Rotatably mounted on theshaft 46 is a sheave 43 for reeling in or taking up one end of aflexible connecting means in the form of a chain 45 that is connected tothe previously mentioned fulcrum 25 of the floating lever I8.

vThe sheave 43 has a concave felly 46, providing a circumferentialworking surface 41 to receive the chain 45. At one point in'itscircumference the sheave is formed with an anchoi-, ing pocket 48whereby the chain 45 may be attached to the sheave. As indicated inFigs. 3 and 6, the walls of the pocket B8 form a radial slot throughwhich one link of the chain may extend with the next adjacent linkinside the pocket positioned transversely of the slot. The

chain may be anchored against dislodgment from will engage the sheave ata relatively great dis-- tance from the sheave axis; in other words,relatively near the concave felly 46. In the construction shown, oneface of the sheave 43 is provided with` two circumferentially spacedlugs`5I and 52 (Fig. 4) for abutment alternately by a third lug 53 thatis integral with a ratchet wheel 55.

As best shown in Fig. 6, the ratchet is mounted on the stub shaft 40adjacent the sheave, and is provided with suitable ratchet wheel 55 4teeth 56 for engagement by a pawl 51. The pawl 51 is mounted on a pivotpin 58 that is secured by a cotter pin 60, and the pawl is suitablybiased toward engagement with the ratchet wheel. As indicated in Fig. 7,gravitational bias of the pawl may be achieved by forming the pawl withan operating arm 6I at an appropriate angle, the operating arm having aneye 62 to receive the looped end 63 of an operating rod 65. The arm 6I,by virtue of its angular position,

tends by gravitation to throw the pawl 51 against the ratchet wheel 55,and such tendency is augmented by the weight of the operating rod 65.

The operating rod 65 extends to the side oi' the car through an aperturein a vertical support plate 66, and is turned downward at its outer endto form an operating handle 61. The vertical support plate 66 is bent toform a fiange 68 at its upper edge, as best shown in Figs. 1 and 2, andis secured to the side sill I0 by suitable rivets 1Il extending throughthe flange.

It is contemplated that force for rotating the sheave 43 in thedirection to take up the chain 45 will be applied directly to the sheaveat a substantial distance from the sheave axis. In my preferredconstruction I provide for this purpose a suitable gear 1I ofapproximately the diameter of the sheave, the gear being directlyconnected.

with the sheave for rotation therewith. In the present construction thegear is actually integral with the sheave, the two being a singlecasting. Thus Fig. 6 shows the gear 1I as an integral lateral extensionof the sheave 43 coaxiall therewith, the extension being formed withperipheral gear teeth 12 in mesh with a pinion 13 of relatively smalldiameter.

The pinion 13 is formed with a radial flange 15 inside the housing 21,and is formed with a hollow hub 16, which hub is journaled in a suitablebearing 11 formed by the wall of the hous-l ing.

Any suitable means may be provided for actuating the pinion 13 from apoint at the side of the car remote from the housing 21. Since thedescribed arrangement of a relatively large gear and a relatively smallpinion provides a vhighly favorable gear ratio for actuation of thesheavel 43, only relatively light operating force need be,

applied to the pinion 13 to take up the chain 45, and thereforerelatively light weight means may be used to transmit actuating forceover the disl tance that separates the housing 21 from the side of thecar. In the present embodiment of the invention I employ a shaft 86, theshaft 8U being.

so much lighter than the usual actuating shaft that it may aptly bedescribed as a light rodl rather than a shaft. It is apparent that thereis no serious risk of brake failure in making the shaft light becausefailure of the shaft would,

not prevent the described ratchet and pawl mechanism from anchoring thechain 45 against,

brake actuating forces. Y

The light shaft 80 is seated at its inner end in the hollow hub 16 ofthe pinion 13, and is suitably.

secured therein by a pin 8l. The outer end of the light shaft 80 extendsthrough the previously mentioned vertical support plate 66, and prefer?ably is journaled therein by an adapter sleeve 8,2, the adapter sleevebeing anchored against axial movement along the shaft by a cotter pin83; l

The shaft 80 may be adapted at its outer endfor manual operation in anysuitable manner., 'Inf the present arrangement I mount a suitable handvwheel 85 on the shaft, the hand Wheel being po, sitioned on the outerside of the vertical support.

plate tit and preferably directly below the side sill l0.

The manner in which the described mechanism operates will be readilyunderstood from the foregoing description. Normally, by virtue of forcetransmitted by the chain t5, the sheave is stationary with the sheavelug 52 in abutment against the ratchet wheel lug 53, as indicated inFig. 4. Whenever it is desired to take up slack in the foundation brakegear the car man will rotate the hand wheel 35 clockwise, as viewed inFig. 2, whereupon the rotation of the pinion 'I3 in mesh with the gearteeth l2 will initially rotate the sheave t3 to carry the sheave lug 52away from the ratchet wheel lug 53, the second sheave lug Ei moving intoabutment with the ratchet wheel lug. Continued rotation of the sheavewith the sheave lug 5l against the ratchet wheel lug 53 will cause theratchet wheel to rotate with the pawl 5l riding over the ratchet teeth.When the tension of the chain 45 prevents further manual rotation thecar man releases the wheel 85, whereupon the force transmitted by thechain causes reverse movement of the sheave until such reverse movementis stopped by abutment of the sheave lug 52 against the ratchet Wheellug 53. The spacing between the faces of the lugs 5l and 53 is such thatthe lost motion just described is suicient to provide proper brake shoeclearance between the brake shoes i5 and the Wheel I6 when the pistonrod i3 is in inoperative or retracted position.

When worn brake shoes l5 are to be replaced by new brake shoes, the carman grasps the handle B1 of the operating rod 65 and pulls the operatingrod outward to cause the pawl 51 to swing out of engagement with theratchet wheel 55. The released ratchet wheel then is free to rotate inits reverse direction along with the sheave 63 in response to forcetransmitted by the chain 45, thereby to provide such slackness in thebrake gear as will permit the installation of the new shoes. After thenew shoes are installed the hand wheel 85 is rotated clockwise, asheretofore described, to take up the slack in the brake gear to therequired extent for resuming operation of the brakes.

The preferred form of my invention described in specific detail hereinwill suggest to those skilled in the art various changes andsubstitutions within the scope of my appended claims.

I claim:

1. In combination with the foundation brake gear of a railway carincluding a dead brake lever, the fulcrum of which is adjustablelongitudinally of the car to effect adjustment of said gear, anadjusting device mounted on the car underframe near the center linethereof, said device comprising a housing, a sheave in the housing, arelatively large driving gear for the sheave, a relatively small piniongear in mesh with the driving gear, a ratchet wheel having a lost motiondriving connection with the sheave corresponding to normal lbrake shoeclearance, a pawl mounted on the housing and cooperating with theratchet wheel to hold the sheave in adjusted position, said sheave,driving and pinion gears and ratchet wheel all being journalled withinsaid housing for rotation about an axis transverse to the longitudinalcenter line of the car, a pinion shaft exu tending to the side of thecar and equipped with means for manual rotation, means for manuallyreleasing the pawl from the ratchet wheel, including a member extendingto a side portion of the car in proximity to Said pinion shaft, and aflexible connector between the brake fulcrum and said sheave adapted tobe wound upon the sheave as the latter is rotated by manipulation ofsaid pinion shaft, said pawl transmitting braking forces through saidhousing directly to the central portion of the car underframe upon whichthe adjusting device is mounted.

2. In combination with the foundation brake gear of a railway carincluding a dead brake lever, the fulcrum of which is adjustablelongitudinally of the car to effect adjustment of said gear, anadjusting device mounted on the car underirame near the center linethereof, said device comprising a housing, a sheave, a ratchet wheelhaving a lost motion driving connection with the sheave corresponding tonormal brake shoe clearance, a pawl mounted on the housing andcooperating with the ratchet wheel to hold the sheave in adjustedposition, said sheave and ratchet wheel being journalled within saidhousing for rotation about an axis transverse to the longitudinal centerline of the car, a shaft for rotating the sheave extending to the sideof the car and equipped with means for manual rotation, said pawl andratchet wheel arrangement including ratchet teeth on a side face of saidwheel with the pawl movable out of engagement with said teeth by a forceexerted transverse to said center line, a pawl actuator operativelyconnected to the pawl and extending to a side portion of the car inproximity to said shaft, and a exible connector between the brakefulcrum and said sheave adapted to be wound upon the sheave as thelatter is rotated by manipulation of said shaft, said pawl transmittingbraking forces through said housing directly to the central portion ofthe car underframe upon which the adjusting device is mounted.

HERBERT E. BARTSCI-I.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

